So far here are the stats:

Red Sox:
Batting averages:
Dustin Pedroia
David Ortiz
Kevin Youkilis

Yankees:
Alex Rodriguez
Nick Swisher
Robinson Cano

Red sox: 0-3 (0 wins, 3 losses!)
Winning percentage: 0%
Yankees: 2-1 (2 wins, 1 loss!)
Winning percentage: 66.67%
On May 9th these are the wins and losses:

wins
losses
Yankees
22
19
Red Sox
22
20
The Red Sox have palyed one more game than the Yankees



On May 3, these are the wins and losses



wins
losses
Yankees
17
9
Red Sox
13
15

This is what we notice:
The Yankees have more wins than the Red Sox.
The Red Sox have more losses than the Yankees.

The Yankees have won 17/26 of their games
The Red Sox have won 13/28.


The Red Sox have played more games - the denominator is bigger!



On April 25th, these are the wins and losses


wins
losses
Yankees
12
6
Red Sox
10
11

Yankee wins: 12/18
losses 6/18


Red Sox wins 10/21
losses 11/21